The invention relates to a method for transporting paper sheets of a relatively small thickness such as the drawing sheets used in plotters and the copying sheets used in copying machines, and in particular to a method for stably transporting such paper sheets into, out of or within said plotters, copying machines or the like, by means of transporting rollers
Each of the plotters comprises a pen such as an automatically controlled drawing means for automatic drawing machines such that a dependent variable is treated as a mathematical function of variables. There are two types of plotters, one of them being such that the sheets of recording paper are transported in a direction "X" by transporting rollers while a recording pen in moved in another direction "Y" perpendicular to the direction of "X". The other plotter is such that the sheet of recording paper is attracted to and fixed in a plane member while only the recording pen is moved in the directions "X" and "Y".
In the known plotters having a mechanism for motion in both the directions "X" and "Y", comparatively thin sheets of recording paper are used which weigh 20 to 50 kg per 1,000 sheets of a size of 1,091.times.788 mm. Such sheets are too flexible for the transporting rollers to transmit their rotational force to the sheets in a moving direction thereof. This prevents an accurate transportation of said sheets, resulting in a lower accuracy of the recorded drawings.
The inventor of the present invention therefore has already proposed an improvement, for which an application was filed in Japan, and which incorporated an adhesive sheet to stick to the recording sheets so as to be held and transported by the transporting rollers.
However, this improvement also has a problem in that the adhesive agent coated on the adhesive sheet brings about unevenness of the surface thereof, thus preventing the recording pen from smoothly running over the recording sheets. Further, the position of coated adhesive agent is to be altered according to a change in the size of recording sheets. Setting operation of the recording sheets becomes uneasy, lowering the efficiency of the drawing works.
On the other hand, the accuracy of reproduction is likely to become poor in certain kinds of copying machines, in particular those of dry copying type, when an original and a thin sheet of copying paper are superposed to be transported into, within and out of the copying machine.